JP2017093148A - Environmental power generation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an environmental power generation apparatus capable of performing thermoelectric power generation by utilizing a heat source of an outside of a housing.SOLUTION: An environmental power generation apparatus comprises a housing 1 and a thermoelectric power generation element 2. The thermoelectric power generation element is disposed so as to be brought into contact with an outer surface of the housing. Thermoelectric materials 23 and thermoelectric materials 24 are alternately disposed. One end (an upper surface side) of each of the thermoelectric materials 23 is connected to one end (an upper surface side) of the thermoelectric material 24 located at a right side (or a left side) of the thermoelectric material 23 by an electric conductor (not illustrated) such as metal. Further, the other end (a lower surface side) of each of the thermoelectric materials 23 is connected to the other end (a lower surface side) of the thermoelectric material 24 located at the left side (or the right side) of the thermoelectric material 23 by the electric conductor (not illustrated) such as the metal. Namely, a plurality of thermoelectric materials 23, 24 is connected in series. Wiring 51 is connected to both ends of the plurality of thermoelectric materials 23, 24 connected in series.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to an energy harvesting apparatus.

  In recent years, energy harvesting that obtains electric power from weak energy sources in the environment has attracted attention. Thermoelectric power generation is known as one method of environmental power generation.

  2. Description of the Related Art Conventionally, as an energy harvesting apparatus using thermoelectric power generation, an apparatus including a casing, a thermoelectric power generation element disposed inside the casing, and a heat source disposed inside the casing has been proposed. In this environmental power generation device, the thermoelectric power generation element is arranged so that one end is in contact with the heat source and the other end is in contact with the inner surface of the casing. With such a configuration, one end of the thermoelectric generator is heated by the heat source, and the other end is cooled by the casing. As a result, a temperature difference occurs between both ends of the heat source power generation element, and thermoelectric power generation is performed.

  However, in the conventional energy harvesting apparatus, since the thermoelectric power generation element is arranged inside the casing, it was not possible to perform thermoelectric generation using a heat source outside the casing.

JP 2011-181880 A

  Provided is an energy harvesting apparatus capable of performing thermoelectric power generation using a heat source outside a housing.

  An environmental power generation device according to an embodiment includes a housing and a thermoelectric power generation element. The thermoelectric generator is disposed so as to contact the outer surface of the housing.

The figure which shows an example of the energy harvesting apparatus which concerns on 1st Embodiment. The figure which shows the other example of the energy harvesting apparatus which concerns on 1st Embodiment. The figure which shows an example of the energy harvesting apparatus which concerns on 2nd Embodiment. The figure which shows the other example of the energy harvesting apparatus which concerns on 2nd Embodiment. The figure which shows the other example of the energy harvesting apparatus which concerns on 2nd Embodiment. The figure which shows an example of the energy harvesting apparatus which concerns on 3rd Embodiment. The figure which shows the other example of the energy harvesting apparatus which concerns on 3rd Embodiment. The figure which shows the other example of the energy harvesting apparatus which concerns on 3rd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
The energy harvesting apparatus according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram illustrating an example of an energy harvesting apparatus according to the present embodiment. The environmental power generation apparatus of FIG. 1 includes a housing 1, a thermoelectric power generation element 2, a power supply circuit 3, an output terminal 4, and wirings 51 and 52.

  The housing 1 is a container in which an electronic device such as the power supply circuit 3 can be stored. The housing 1 serves as a heat sink that cools one surface of the thermoelectric generator 2. For this reason, it is preferable that the housing | casing 1 is formed with a material with high heat conductivity. Specifically, the housing 1 is preferably formed of a metal such as aluminum.

  Moreover, the housing | casing 1 has a wiring hole. The wiring hole is a through hole provided in the housing 1 for passing the wiring. By providing the wiring hole, the electronic device inside the housing 1 and the device outside the housing 1 (hereinafter referred to as “external device”) can be connected by wiring.

  In the example of FIG. 1, the housing 1 has two wiring holes 11 and 12. The wiring hole 11 is a through hole through which the wiring 51 passes. The wiring hole 12 is a through hole through which the wiring 52 passes.

  In the example of FIG. 1, the wiring holes 11 and 12 are both provided on the side surface of the housing 1, but may be provided on the upper surface or the lower surface of the housing 1.

  Further, the housing 1 may be provided with three or more wiring holes, or may not be provided with the wiring holes 12 as shown in FIG.

  Further, the space between the wiring hole of the housing 1 and the wiring passed through the wiring hole may be closed by a resin packing or the like. Thereby, the inside of the housing | casing 1 can be sealed and the waterproofness of an energy harvesting apparatus can be improved.

  The thermoelectric power generation element 2 is a flat element that performs thermoelectric power generation. When a temperature difference is generated between one surface and the other surface, the thermoelectric generator 2 generates a voltage corresponding to the generated temperature difference. The thermoelectric generator 2 is arranged such that one surface or the other surface is in contact with the outer surface of the housing 1. The thermoelectric power generation element 2 includes insulator plates 21 and 22 and thermoelectric materials 23 and 24.

  The insulator plate 21 is a plate-like member that constitutes the upper surface of the thermoelectric generator 2 and is formed of an insulator. The insulator plate 21 is in contact with the lower surface of the housing 1. The insulator plate 21 insulates the thermoelectric materials 23 and 24 from the housing 1.

  The insulator plate 22 is a plate-like member that constitutes the lower surface of the thermoelectric generator 2 and is formed of an insulator. The insulator plate 22 insulates the thermoelectric materials 23 and 24 from the housing 1.

  A plurality of thermoelectric materials 23 are arranged between the insulator plate 21 and the insulator plate 22 in the plane direction of the thermoelectric power generation element 2. The thermoelectric material 23 is, for example, an N-type semiconductor or a metal.

  A plurality of thermoelectric materials 24 are arranged between the insulator plate 21 and the insulator plate 22 in the plane direction of the thermoelectric power generation element 2. The thermoelectric material 24 is, for example, a metal different from the P-type semiconductor or the thermoelectric material 23.

  In the example of FIG. 1, the thermoelectric material 23 and the thermoelectric material 24 are alternately arranged. One end (upper surface side) of each thermoelectric material 23 is connected to one end (upper surface side) of the thermoelectric material 24 on the right side (or left side) of the thermoelectric material 23 by a conductor (not shown) such as metal. The other end (lower surface side) of the thermoelectric material 23 is connected to the other end (lower surface side) of the thermoelectric material 24 on the left side (or right side) of the thermoelectric material 23 by a conductor (not shown) such as metal. Yes. That is, the plurality of thermoelectric materials 23 and 24 are connected in series. Wiring 51 is connected to both ends of the thermoelectric materials 23 and 24 connected in series.

  When there is a heat source on the lower surface side of the thermoelectric power generation element 2, the lower surface of the thermoelectric power generation element 2 is heated by the heat source. On the other hand, the upper surface of the thermoelectric power generation element 2 is heated by the heat source, and at the same time, is radiated by the casing 1 and cooled. As a result, the temperature of the upper surface of the thermoelectric generator 2 becomes lower than the temperature of the lower surface. That is, a temperature difference is generated between the upper surface and the lower surface of the thermoelectric generator 2.

  The thermoelectric generator 2 generates a voltage corresponding to this temperature difference. When the temperature difference is about several K, the generated voltage is, for example, several tens of mV. The thermoelectric power generation element 2 outputs output power corresponding to the generated voltage.

  In the example of FIG. 1, the thermoelectric power generation element 2 is disposed so that the upper surface thereof is in contact with the lower surface of the housing 1, but may be disposed so as to be in contact with the side surface or the upper surface of the housing 1. Further, the thermoelectric power generation element 2 may be disposed such that the lower surface thereof is in contact with the outer surface of the housing 1.

  The wiring 51 is a power supply line that connects between the thermoelectric generator 2 and the power supply circuit 3. The wiring 51 is passed through the wiring hole 11 of the housing 1. The output power of the thermoelectric generator 2 is input to the power supply circuit 3 through the wiring 51.

  The power supply circuit 3 is disposed inside the housing 1. The power supply circuit 3 includes a booster circuit, and boosts the output power of the thermoelectric generator 2 input via the wiring 51 to a desired voltage (for example, about several volts). The power supply circuit 3 outputs output power corresponding to the boosted voltage.

  The power supply circuit 3 may include a storage element (battery or capacitor) that stores the output power of the thermoelectric power generation element 2. In addition, a power storage element that is a separate member from the power supply circuit 3 may be provided inside the housing 1.

  In the example of FIG. 1, the power supply circuit 3 is disposed so as to be in contact with the lower surface of the housing 1, but may be disposed so as to float from the lower surface by a spacer or the like. Thereby, the heat of the power supply circuit 3 can be hardly transmitted to the lower surface of the housing 1, and the cooling efficiency of the upper surface of the thermoelectric power generation element 2 by the housing 1 can be improved. The power supply circuit 3 may be disposed on the upper surface of the housing 1 or may be disposed on the side surface.

  The wiring 52 is a power supply line that connects the power supply circuit 3 and the output terminal 4. The wiring 52 is passed through the wiring hole 12 of the housing 1. The output power of the power supply circuit 3 is output from the output terminal 4 via the wiring 52.

  The output terminal 4 is a terminal that can be connected to a power supply terminal of an external device. The energy harvesting apparatus according to the present embodiment supplies the output power of the power supply circuit 3 to an external device via the output terminal 4. The external device can obtain the output power of the power supply circuit 3 by connecting the output terminal 4 to the power supply terminal.

  As described above, the environmental power generation device according to the present embodiment boosts the power generated by the thermoelectric power generation element 2 by the power supply circuit 3 and supplies the boosted power to the external device via the output terminal 4. Since the output power of the thermoelectric power generation element 2 is boosted by the power supply circuit 3, the environmental power generation device can supply output power of an appropriate voltage to the external device.

  Further, since the thermoelectric power generation element 2 is provided outside the housing 1, it can generate power using a heat source outside the housing 1.

  In addition, since the housing 1 serves as a heat sink for cooling the upper surface (or lower surface) of the thermoelectric generator 2, it is not necessary to provide a dedicated heat sink for the thermoelectric generator 2. Thereby, an energy harvesting apparatus can be reduced in size.

  The energy harvesting apparatus according to the present embodiment described above can be used as a power source for sensors, wireless communication devices, and the like (hereinafter referred to as “sensors”) installed near a heat source. As an example, a case will be described in which the energy harvesting apparatus of FIG. 1 is used as a power source for a sensor or the like installed in the vicinity of an automobile engine, motor, exhaust pipe, or the like (hereinafter referred to as an “engine”).

  In this case, the user of the energy harvesting device installs the energy harvesting device so that the lower surface of the thermoelectric power generation element 2 is in contact with or close to the engine serving as a heat source. Further, the user installs a sensor or the like at a desired position. Then, the user connects the output terminal 4 and a power supply terminal such as a sensor.

  As a result, as long as the engine or the like is heated, power is supplied from the energy harvesting device to the sensor or the like, and the sensor or the like can be continuously driven.

  FIG. 2 is a diagram illustrating another example of the energy harvesting apparatus according to the present embodiment. In the energy harvesting apparatus of FIG. 2, the housing 1 includes the heat radiation fins 13. The heat radiating fins 13 are provided so as to protrude from the outer surface of the housing 1. Other configurations are the same as those in FIG.

  Thus, by providing the radiation fins 13 on the outer surface of the housing 1, the surface area of the housing 1 is increased. As a result, the heat dissipation efficiency of the housing 1 is improved, and the cooling effect of the upper surface of the thermoelectric power generation element 2 by the housing 1 can be improved.

  In the example of FIG. 2, the radiating fins 13 are provided on the side surface and the upper surface of the housing 1, but may be provided on either the side surface or the upper surface. Further, the heat radiating fins 13, which are members different from the housing 1, may be attached so as to contact the outer surface of the housing 1.

(Second Embodiment)
The energy harvesting apparatus according to the second embodiment will be described with reference to FIGS. The energy harvesting apparatus according to the present embodiment uses vibration power generation together with thermoelectric power generation. FIG. 3 is a diagram illustrating an example of the energy harvesting apparatus according to the present embodiment. The energy harvesting apparatus of FIG. 3 includes a piezoelectric element 6, a spacer 61, a weight 62, and a wiring 53. Other configurations are the same as those in FIG.

  The piezoelectric element 6 is a plate-shaped or rod-shaped element that performs vibration power generation. The piezoelectric element 6 generates a voltage corresponding to the applied pressure. In the example of FIG. 3, the piezoelectric element 6 is disposed inside the housing 1.

  The spacer 61 is a rod-shaped or plate-shaped member with one end fixed to the inner surface of the housing 1. One end of the piezoelectric element 6 is fixed to the other end of the spacer 61. Thereby, one end of the piezoelectric element 6 is fixed to the housing 1.

  The weight 62 is fixed to the other end of the piezoelectric element 6.

  The piezoelectric element 6, the spacer 61, and the weight 62 constitute a cantilever beam. When the housing 1 vibrates, the piezoelectric element 6 vibrates due to this vibration. The piezoelectric element 6 generates a voltage corresponding to the pressure generated on the vibration surface. When the piezoelectric element 6 generates a voltage, it outputs output power corresponding to the generated voltage. The amount of power generated by the piezoelectric element 6 is maximized when the vibration of the housing 1 matches the resonance frequency of the cantilever. The resonant frequency of the cantilever can be adjusted by the weight of the weight 62.

  The wiring 53 is a power supply line that connects the piezoelectric element 6 and the power supply circuit 3. The output power of the piezoelectric element 6 is input to the power supply circuit 3 via the wiring 53.

  As described above, in the environmental power generation device according to this embodiment, the power generated by the thermoelectric power generation element 2 by thermoelectric power generation and the power generated by the piezoelectric element 6 by vibration power generation are input to the power supply circuit 3. Thus, the power generation amount of the energy harvesting apparatus can be increased by using two types of energy harvesting together.

  Further, when the piezoelectric element 6 vibrates, the air inside the housing 1 is agitated, and the heat distribution inside the housing 1 is made uniform. As a result, the heat dissipation efficiency of the housing 1 is improved, and the cooling effect of the upper surface of the thermoelectric power generation element 2 by the housing 1 can be improved.

  In the example of FIG. 3, the energy harvesting apparatus includes only one piezoelectric element 6, but may include a plurality of piezoelectric elements 6. In this case, a spacer 61, a weight 62, and a wiring 53 may be provided for each piezoelectric element 6.

  FIG. 4 is a diagram illustrating another example of the energy harvesting apparatus according to the present embodiment. In the energy harvesting apparatus of FIG. 4, the piezoelectric element 6 is disposed outside the housing 1. For this reason, the housing 1 is provided with a wiring hole 14 through which the wiring 53 passes. Further, since one end of the piezoelectric element 6 is directly fixed to the side surface of the housing 1, the spacer 61 is not provided. Other configurations are the same as those in FIG.

  Even with the configuration of FIG. 4, it is possible to increase the power generation amount of the environmental power generation device by using the vibration power generation by the piezoelectric element 6. Moreover, since the piezoelectric element 6 plays a role as a heat radiating fin, the heat dissipation efficiency of the housing 1 is improved, and the cooling effect of the upper surface of the thermoelectric power generation element 2 by the housing 1 can be improved.

  In the example of FIG. 4, the energy harvesting apparatus includes only one piezoelectric element 6, but may include a plurality of piezoelectric elements 6. In this case, the weight 62, the wiring 53, and the wiring hole 14 may be provided for each piezoelectric element 6. The piezoelectric element 6 may be fixed to the other end of the spacer 61 having one end fixed to the outer surface of the housing 1. In addition, the piezoelectric element 6 may be provided inside the housing 1 and outside the housing 1.

  FIG. 5 is a diagram illustrating another example of the energy harvesting apparatus according to the present embodiment. The energy harvesting apparatus in FIG. 5 includes two piezoelectric elements 6A and 6B. The piezoelectric elements 6A and 6B are respectively fixed with weights 62A and 62B having different weights. Other configurations are the same as those in FIG.

  With such a configuration, the resonance frequency of the cantilever formed by the piezoelectric element 6A is different from the resonance frequency of the cantilever formed by the piezoelectric element 6B. That is, the frequency of vibration of the housing 1 that maximizes the amount of power generated by the piezoelectric element 6A is different from the frequency of vibration of the housing 1 that maximizes the amount of power generated by the piezoelectric element 6B. Thereby, the frequency band of the vibration of the housing | casing 1 in which an environmental power generation device can perform vibration electric power generation can be expanded.

  The energy harvesting apparatus may include three or more piezoelectric elements 6, and weights 62 having different weights may be fixed to the respective piezoelectric elements 6.

(Third embodiment)
An energy harvesting apparatus according to a third embodiment will be described with reference to FIGS. 6 and 7. In each of the above embodiments, it is assumed that the energy harvesting apparatus is used as a power source for an external device. On the other hand, this embodiment demonstrates the energy harvesting apparatus comprised integrally with a sensor, a radio | wireless communication apparatus, etc. FIG. 6 is a diagram illustrating an example of the energy harvesting apparatus according to the present embodiment. The energy harvesting apparatus of FIG. 6 includes a sensor 7, a wireless communication device 8, a radio wave transmission unit 9, and wirings 54 to 56. In addition, since the sensor or the like is integrated with the housing 1, the energy harvesting apparatus does not include the output terminal 4. Other configurations are the same as those in FIG.

  The sensor 7 is disposed inside the housing 1. The environmental power generation device can be mounted with any sensor such as an acceleration sensor, a temperature sensor, a gas sensor, a magnetic sensor, or a pressure sensor as the sensor 7. In addition, the energy harvesting apparatus may include a plurality of sensors 7.

  The wireless communication device 8 is disposed inside the housing 1. The wireless communication device 8 is a wireless transmitter that wirelessly transmits sensing data of the sensor 7. The wireless communication device 8 may be a wireless transceiver that can receive data wirelessly.

  The radio wave transmission unit 9 is a part that is provided in at least a part of the housing 1 and can transmit radio waves. In the example of FIG. 6, the radio wave transmission unit 9 is made of a radio wave transmission material that can transmit radio waves. Examples of the radio wave transmitting material include resin and glass. The radio wave output from the wireless transmitter 8 is transmitted to the outside of the housing 1 through the radio wave transmission unit 9. Therefore, the radio wave transmitting unit 9 is preferably provided in the vicinity of the antenna of the wireless communication device 8.

  In the example of FIG. 6, the radio wave transmission unit 9 is provided on the upper surface of the housing 1, but may be provided on a side surface. One radio wave transmitting unit 9 may be provided or a plurality of radio wave transmitting units 9 may be provided.

  The wiring 54 is a power supply line that connects the power supply circuit 3 and the sensor 7. The output power of the power source 3 is supplied to the sensor 7 via the wiring 54. The sensor 7 is driven by electric power supplied from the power supply circuit 3.

  The wiring 55 is a power supply line that connects the power supply circuit 3 and the wireless communication device 8. The output power of the power source 3 is supplied to the wireless communication device 8 via the wiring 55. The wireless communication device 8 is driven by the power supplied from the power supply circuit 3.

  The wiring 56 is a signal line that connects the sensor 7 and the wireless communication device 8. Sensing data of the sensor 7 is input to the wireless communication device 8 via the wiring 56. The wireless communication device 8 transmits the sensing data input from the sensor 7 wirelessly.

  With the above configuration, the energy harvesting device, the sensor 7, and the wireless communication device 8 can be configured integrally.

  Further, since the sensor 7 and the wireless communication device 8 are arranged inside the housing 1, it is not necessary to wire a power supply line or a signal line outside the housing 1. Therefore, the degree of freedom of installation of the sensor 7 and the wireless communication device 8 can be improved as compared with the case where the energy harvesting device and the external device are connected.

  In the energy harvesting apparatus of FIG. 6, the radio wave transmission unit 9 is made of a radio wave transmission material. Thereby, the inside of the housing | casing 1 can be sealed and the waterproofness of an energy harvesting apparatus can be improved.

  FIG. 7 is a diagram illustrating another example of the energy harvesting apparatus according to the present embodiment. In the energy harvesting apparatus of FIG. 7, the sensor 7 is disposed outside the housing 1. For this reason, the housing 1 is provided with a wiring hole 15 through which the wirings 54 and 55 are passed. Other configurations are the same as those in FIG.

  With such a configuration, the energy harvesting apparatus and the wireless communication device 8 can be configured integrally. Further, by arranging the sensor 7 outside the housing 1, the sensor 7 can sense the environment outside the housing 1.

  The housing 1 may be provided with a wiring hole for passing the wiring 54 and a wiring hole for passing the wiring 56. It is also possible to arrange the sensor 7 inside the housing 1 and the wireless communication device 8 outside the housing 1.

  FIG. 8 is a diagram illustrating another example of the energy harvesting apparatus according to the present embodiment. The energy harvesting apparatus of FIG. 8 includes a vent 10 instead of the radio wave transmission unit 9. The vent 10 is a through hole provided in the upper surface of the housing 1 and plays a role of the radio wave transmitting portion 9 in FIG. That is, the radio wave output by the wireless communication device 8 is transmitted to the outside of the housing 1 through the vent hole 10. Other configurations are the same as those in FIG.

  In the energy harvesting apparatus of FIG. 8, the inside of the housing 1 is not sealed but is ventilated through the radio wave transmission unit 9 (ventilation port). Thereby, since the air inside the casing 1 heated by the thermoelectric generator 2 is discharged, the heat dissipation efficiency of the casing 1 is improved, and the cooling effect of the upper surface of the thermoelectric generator 2 by the casing 1 is improved. be able to.

  One vent hole may be provided or a plurality of vent holes may be provided. As shown in FIG. 8, by providing a plurality of vent holes, the air permeability of the housing 1 can be improved, and the cooling effect of the upper surface of the thermoelectric generator 2 by the housing 1 can be further improved.

  In the example of FIG. 8, the vent is provided on the upper surface of the housing 1, but may be provided on the side surface of the housing 1, or may be provided on both the upper surface and the side surface.

  Note that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. Further, for example, a configuration in which some components are deleted from all the components shown in each embodiment is also conceivable. Furthermore, you may combine suitably the component described in different embodiment.

DESCRIPTION OF SYMBOLS 1: Case, 2: Thermoelectric power generation element, 3: Power supply circuit, 4: Output terminal, 6: Piezoelectric element, 7: Sensor, 8: Wireless communication device, 9: Radio wave transmission part, 10: Vent, 11, 12 14, 15: Wiring holes, 13: Radiation fins, 21, 22: Insulator plates, 23, 24: Thermoelectric materials, 51-56: Wiring, 61: Spacers, 62: Weights

Claims (12)

A housing,
A thermoelectric generator arranged to contact the outer surface of the housing;
An energy harvesting apparatus comprising: The energy harvesting apparatus according to claim 1, further comprising a power supply circuit that is disposed inside the housing and receives output power of the thermoelectric power generation element. The energy harvesting apparatus according to claim 1 or 2, wherein the casing is made of metal. The energy harvesting apparatus according to any one of claims 1 to 3, wherein the casing has at least one wiring hole. The energy harvesting apparatus according to any one of claims 1 to 4, wherein the casing includes a heat radiation fin on at least a part of an outer surface. Comprising a piezoelectric element disposed inside the housing;
6. The energy harvesting apparatus according to claim 2, wherein output power of the piezoelectric element is input to the power supply circuit. 7. The energy harvesting apparatus according to claim 6, wherein one end of the piezoelectric element is fixed to the housing. The energy harvesting apparatus according to any one of claims 2 to 7, further comprising a wireless communication device that is disposed inside the casing and is supplied with electric power from the power supply circuit. The energy harvesting apparatus according to any one of claims 2 to 8, further comprising a sensor that is disposed inside the housing and is supplied with electric power from the power supply circuit. The energy harvesting apparatus according to any one of claims 1 to 9, wherein the casing includes a radio wave transmission unit capable of transmitting radio waves. The environmental power generation device according to claim 10, wherein the radio wave transmission unit is formed of a radio wave transmission material capable of transmitting radio waves. The energy harvesting apparatus according to claim 1, wherein the housing includes a vent hole.

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